according to harrod domar model the level of savings remain constant to the proportion of income.
Harrod-Domar model assumes a simple production function y=f(k), where k is capital

difference between horred-domer and solow model

It assumes that savings and investment are all that is needed for growth. No diminishing returns to capital is an implicit assumption.

By the Harrod-Domar model, net investment should be greater than depreciation rate or there should be an increase in the productivity of the factors of production.

Domar serfdom model was created in 1970.